1. Field of the Invention
This invention pertains to agricultural equipment, and more particularly to apparatus that transfers agricultural products from a wheeled vehicle to a blower or similar conveying implement.
2. Description of the Prior Art
Various types of machines have been developed to harvest agricultural crops. A harvesting machine often loads the picked crop into a box of a vehicle that travels in the field along with the machine. When the vehicle box is full, it is driven to a barn or similar site for unloading. After the vehicle has been emptied, it returns to the field for another load, and the loading-unloading cycle repeats.
Vehicles that carry and unload harvested crops are available with a wide variety of structural and operational features. Some prior crop carrying and unloading vehicles had apron chains that propelled the crop in the box in a longitudinal direction. Some prior vehicles also had cross chains or augers that discharged the crop out one or other side of the box. Typical examples of chain and auger type unloading vehicles may be seen in U.S. Pat. Nos. 2,321,168; 2,743,832; 3,047,173; 3,047,174; 3,173,563; 3,189,202; 3,286,862; 3,512,668; 3,873,032; 3,819,072; and 4,049,145.
A common characteristic of the vehicles of the foregoing patents was that they were not self-powered. Rather, they were in the form of wagons that were pulled from place to place by a powered vehicle such as a tractor. In addition, an external source of power was required to operate the wagon apron chains or other unloading mechanisms. Typically, the unloading mechanisms of the wagons were connected to a power take-off unit of the tractor.
Prior wagons with cross chains or augers were suitable for unloading a crop in a concentrated stream to a blower, conveyor, or similar conveying implement that is commonly used to fill a silo. However, the speed with which the prior wagons could unload was undesirably slow. Another major limitation, as mentioned, was the lack of power on the wagon itself for operating the unloading mechanism. With some crops and operating conditions, the power available from a tractor was only marginally sufficient. In those situations, there was a danger that the tractor could overheat or otherwise be damaged. As a result, the wagon-tractor combination for carrying and unloading crops was not entirely satisfactory.
The use of trucks with large boxes for carrying harvested crops from a field to a storage location is becoming increasingly common, because trucks have increased versatility and economy compared with tractors and wagons. However, trucks for carrying and unloading agricultural crops possess an important disadvantage. That disadvantage is based on the fact that a truck cannot conveniently unload the crop in a small and concentrated stream onto a blower or conveyor. Merely dumping the truck box is not acceptable, because a truck can dump its load much faster than a blower or other implement can move the material away. In addition, the material falls from a truck box across its entire width, not in a concentrated stream. Consequently, trucks cannot be used to transfer the crop to conventional blowers or other conveying implements unless the farmer is willing to tolerate either a large amount of spillage or a lengthy wait for a person to carefully and slowly hand shovel the crop onto the blower. The wait for the truck to be unloaded by hand represents unproductive use of both the truck and its driver.
The Meyer Manufacturing Corporation of Dorchester, Wis., markets a forage box with apron chains that is suitable for use with a self-propelled vehicle, such as a large truck. Power to operate the apron chains is available directly from the truck such that the forage box and truck constitute a self-contained crop carrying and unloading system.
Thus, a need exists for improvements in transferring harvested crops to storage locations.